The Linux option

by Simon Bisson

Can a modern Linux distribution help you get more bang for the buck out of existing server hardware?

Linux isn’t the new kid on the block any more: the open source UNIX-derived operating system has been around since 1991. Over the last 22 years it’s gone from plucky underdog to become the platform that underlies many of the world’s largest cloud services. Most businesses have at least one Linux system in their network, and it’s the foundation of many business critical services – running reliably and securely. So if you’re running other operating systems, on desktops and in servers, is it worth another look?

There are many Linux distributions, all building on the same kernel, but they offer different packages of software and different tunings. Some let you build your own Linux installations from scratch, while others come with all the tools and services you’ll need. Amongst the latter are Red Hat’s Enterprise Linux (RHEL) and Oracle Linux.

Red Hat was one of the pioneers of commercial Linux, founded in 1993 and delivering its first distribution a year later. Now it sponsors the Fedora project which pioneers technologies that transfer into its supported Red Hat products. With a relatively conservative release cycle, Red Hat Enterprise Linux is intended to be an IT department-friendly distribution that provides regular security and software updates, without making major changes. Fedora’s 6 monthly release cycle feeds into RHEL’s roughly bi-annual releases. The current release of RHEL will be supported until 2023, and the next major release, RHEL 7, is due in the second half of 2013.

RHEL is provided through a subscription service, and you need to choose a subscription appropriate to your organisation’s needs. Subscription pricing varies by installation type, with a desktop installation being significantly cheaper than a server installation. Server options include two and four sockets, and one, four or unlimited guest operating systems.

Although there are many installation options for servers, desktops and workstations, Red Hat bundles them all into a single installation CD which can be downloaded as an ISO image (ideal for installing as a guest OS under VMware or Hyper-V). RHEL’s graphical installer gives you various installation options, from a bare bones GUI-less server to a full graphical desktop on a development workstation. You can then use the built-in software package management tools to update the tools and services you’ve installed, and add new features from Red Hat’s various repositories.

Red Hat’s platform goes beyond the basic server, with a range of enterprise grade add-ons that compare favourably with many proprietary tools and services. These include tools for building high-availability servers, which can be used alongside resilient storage servers and load-balancers to build reliable services – across multiple data centres. Other options add virtualisation features, increase scalability or add additional management capabilities.

Linux in action

This is what Ferrotec used for its new data centre, built on Cisco hardware. The company makes a magnetic liquid, and its business has expanded rapidly over the last few years, leaving its mix of legacy IT systems struggling to cope. The company decided to take the opportunity to modernise its systems, and to build a new virtualised data centre. As many of its current systems used Linux, the IT team worked with a Red Hat partner to put together a new network. Using Red Hat’s Enterprise Virtualisation tools the company was able to replace seven old servers with two new Cisco systems, hosting eight virtual machines. There’s enough overhead for expansion, and a virtualised infrastructure like this adds redundancy while also saving money.

The subscription option Ferrotec chose also means they can run a further 12 virtual machines without additional charge – and Red Hat’s administration tools simplify system management so that the IT team can quickly spin up those new servers. Joachim Schwender, head of IT at Ferrotec, said, “We don’t have to make compromises between performance, flexibility, and administration requirements.”

Similarly the Canary Islands government moved its telecoms servers to Red Hat’s platform from VMware, with a significant increase in capacity. Machines that had hosted only 7 virtual machines can now support 27. The IT team was able to upgrade 100 servers in four months, without having to buy new hardware.

You can choose additional features during installation.

While Linux may not be the natural choice for the average user’s desktop, the desktop versions of Red Hat and Oracle’s Linux are powerful development tools. With Linux still the platform of choice for much Web and Internet service development, a desktop OS that runs the same servers and applications as the final deployment targets makes a lot of sense – and with support for Linux in Microsoft’s Hyper-V, in VMware, and in the free VirtualBox, it’s easy to have it running alongside Windows on a development PC.

RHEL remains popular, but the standard bearer for desktop Linux is Canonical’s Ubuntu. The development team behind Ubuntu recently unveiled ambitious plans to deliver a single operating system – and a single user experience – that runs on everything from smartphones to tablets to PCs. Developers wanting to stay close to the bleeding edge are likely to prefer Fedora, working with new technologies that will be in future releases of RHEL.

Getting started

Getting started with a modern Linux is relatively simple. Back in the early days, installations used to require much more in the way of low level configuration, defining disk partitions and choosing just how much disk space to allocate for swap. That’s all changed with modern installers which offer a simple graphical approach to installation. You do need to choose the type of installation you’re going to be using, from basic servers to development workstations, but essentially all you do is insert the boot media and follow the instructions.

Linux’s modular nature comes into play in the installers for both RHEL and Oracle Linux. You choose the type of server you want to set up, and the installer does the rest. While most server installs leave you with just a command line, you can add a GUI from the bundled package manager. Linux package managers simplify application installation and configuration, ensuring that all the required packages are installed – including additional software that may be needed to support a particular application or function.

Linux is also an option for departmental servers, especially in conjunction with the familiar LAMP Web stack which allows teams to develop their own apps and then take advantage of hosted cloud services if they need extra capability.

Setting up RHEL as a Web server installs the Apache web server, the MySQL database and the PHP scripting language. You can also add support for popular NoSQL storage environments, and newer development tooling such as Ruby on Rails and Node.js. The same combination of tools can be installed on a development server, giving developers tools for quickly debugging production applications, and simplifying test and deployment as projects move from development into operation.

RHEL keeps itself up-to-date with security patches and new versions of installed software.

Of course you don’t need to set up RHEL yourself. A cloud hosting provider can provide you with RHEL images ready to deploy and often already configured as Web or database servers. Services like Amazon EC2 offer RHEL alongside other popular Linux distributions including Oracle Enterprise Linux, SUSE Linux, Fedora, Ubuntu and Amazon’s own Linux AMI. You can select from a range of pre-configured images, using the appropriate image for the task you have in mind, ranging from small images for Web servers to cluster images for complex, processor intensive tasks. Using RHEL in the cloud allows you to quickly transfer workloads or whole server images out of your data centre as and when needed, making your IT more flexible and more scalable.

Oracle Linux

If you’re using a recent Oracle appliance then you’re already running Oracle Linux. That includes its Database Appliance and its Exadata and Exalogic servers. Oracle Linux is a derivative of Red Hat Linux, with the option of switching to Oracle’s own kernel from the default Red Hat compatible kernel. Oracle’s own Unbreakable Enterprise kernel is described as compatible with Red Hat and has been certified for use with Oracle’s own applications, which are developed on the platform. Much like RHEL, Oracle Linux has a support option, or you can download it for free. As RedHat and Oracle Linux are so similar you’re unlikely to want to use Oracle Linux unless you’re using Oracle’s own server and middleware software which take advantage of the scalability and multiprocessing features built into Oracle’s own kernel.

Oracle also adds its own tooling, including the Solaris Dtrace debugging tools. If you’re building large scale enterprise applications then Dtrace’s probes can simplify finding problems and will help deliver comprehensive reports to developers. Similarly Ksplice support means you can patch the kernel on the fly. There’s also support for Oracle’s own virtualisation and containerisation tools, giving you a platform for server consolidation.

Linux comes into its own when used to revitalise older hardware. A server due for retirement can be repurposed as a departmental system, or set up as a storage or security appliance. Reusing older hardware like this can lead to significant savings, extending hardware life and providing IT infrastructure where it’s most needed.

With enterprise grade products from Red Hat and Oracle, and innovative options from Canonical, it’s clear that Linux remains a powerful tool for any business, and more than capable of supporting key business operations. Commercially supported Linux distributions may not be as low cost as freely available options, but IT organisations will appreciate fixed lifecycles and support contacts, especially when those Linux servers are critical infrastructure. Support for the same platforms by cloud providers simplifies scaling of datacentres and applications, letting you take advantage of someone else’s infrastructure when you need extra processing power but don’t have the budget or the space for extra servers.